1. Technical Field of the Invention
The present invention relates, generally, to a composition, and method of use therefor, of iodophor teat dips for the prevention of bacterial infections in a mammal's udder. More particularly, the present invention relates to the prevention of bovine mastitis through the use of antimicrobial buffering agents for iodophor teat dip disinfectants.
2. Description of the Prior Art
As a result of selective breeding, man has produced dairy cattle having mammary glands with a milk-secreting potential far in excess of the requirements of the newborn calf. Because of the size, position and anatomic adjustment for rapid removal of large volumes of milk, the udders of present diary cows are especially prone to injury and infection. The resulting inflammation is called mastitis, which causes an estimated $2 billion annual loss in U.S. milk production.
Faulty managerial practices can control both sources of mastitis, trauma and bacterial infection. In the latter regard, experience has indicated that its frequency among cows in a herd, and the intensity of infections may be lessened by proper use of antimicrobial materials. These antimicrobials take the form of pre-milking teat-washing sanitizers and have been modified in recent years through inclusion of polymeric materials which deposit a film barrier over the surface of the teat, for helping to minimize transfer of residual and/or newly-deposited microorganisms into the teat interior.
It has been estimated that more than half the cows the United States have some type of mastitis, which are classified into two forms. These are "clinical," characterized by detectable changes in milk and gland, and "sub-clinical," where the infection is not directly evident. Microscopic examination of milk from sub-clinically-mastitic cows shows increased levels of white cells and often the causative bacteria. Most mastitis infections are in the latter category. "Contagious" mastitis, caused by the microorganisms Strep, agalactiae and Staph, aureus, is associated with infections which arise primarily by the transfer of these microorganisms from one cow to the next by contamination of milking equipment and milkers'hands during the milking procedure.
A broader range of organisms are associated with "environmental" mastitis. This derives from the contamination of the cow's udder by microorganisms which contact the teat between milkings, such as from wind-borne matter, bedding material and other ground contaminants (e.g., soil, manure) that contact the gland when the animal lies down. Environmental organisms include the coliforms, Escherichia coli, Klebsiella pneumoniae, Enterobacter spp. and Citrobacter spp., as well as Strep. uberis, Strep. dysgalactiae, and Pseudomonas aeruginosa.
The pre- and post-milking teat dips, including the barrier formers, generally contain antimicrobials of the following classes: iodophors, quaternary ammonium compounds, chlorhexidine, sodium hypochlorite, hydrogen peroxide, organic acids (e.g., lactic, lauric), dodecylbenzene sulfonic acid, chlorous acid and bacteriocins. Many of these are very effective in destroying mastitis-causing organisms upon contact and, thus, are effective in protecting against contagious mastitis, but have limited effectiveness in preventing against environmental mastitis. During the 8-12 hour intermilking period, insufficient amounts of these antimicrobias remain to destroy invading microorganisms. Even barrier-forming teat dips, and iodophor test dips, which deposit free iodine that is substantive to skin tissue, still leave large numbers of cows susceptible to mastitis caused by environmental microorganisms.
The search has continued for a means for extending the protective effects of current teat dip technologies, to further minimize the incidence of environmental mastitis. The present invention, a result of experimental studies designed to meet this need, is the discovery of a procedure for augmenting the antimicrobial activity associated with iodophor teat dips. The present invention, an improved disinfection system, can be applied to standard antimicrobial teat dips or to the newly-emerging, barrier-forming polymer compositions in order to further expand the protection afforded by antimicrobial iodophor teat dips against environmental mastitis.